You might try a valve kit that JD has, here is the link to the JD online parts site for that: John Deere Parts Catalog
JD 4400 Dual SCV problems
Howdy all,
I'm looking for some help with the spool valve on my 4400. I was using the front mount blower on my tractor when the joystick for SCV control started to bind in the forward / backward positions. I thought it might just be some dirt in the linkages that connect the joystick to the spool on the valve, but after giving everything a good spray/cleaning the problem remains.
I've since removed the spool valve from the tractor and am attempting to diagnose where the problem lies. The fluid that was remaining in the valve body was fairly black. The spools themselves look to be in good condition with no marks / roughness except along some of the machined edges (where the hydraulic fluid flows through). The valve body also appears fairly decent, but I can feel some roughness on the bored out machined edges on the inside. When I try to reinsert the spool into the cavity it goes smoothly until about halfway through and then binds. I tried to swap out the third unused spool with the spool that was binding but had similar results, so I think the problem lies in the valve body.
Does anyone have any experience servicing one of these valves? Is it worth my time to try and refurb this? I can't find any used valves on ebay and new units come in around $1200 - $1500. I've attached some pictures to try and give you a better idea of what I'm working with. Any and all suggestions appreciated. Let me know if any more info is required.
Spool valve - JD# AM124970 (dukes# 1415-AG / 156B7015)
Tractor - LV4400H
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I'm looking for some help with the spool valve on my 4400. I was using the front mount blower on my tractor when the joystick for SCV control started to bind in the forward / backward positions. I thought it might just be some dirt in the linkages that connect the joystick to the spool on the valve, but after giving everything a good spray/cleaning the problem remains.
I've since removed the spool valve from the tractor and am attempting to diagnose where the problem lies. The fluid that was remaining in the valve body was fairly black. The spools themselves look to be in good condition with no marks / roughness except along some of the machined edges (where the hydraulic fluid flows through). The valve body also appears fairly decent, but I can feel some roughness on the bored out machined edges on the inside. When I try to reinsert the spool into the cavity it goes smoothly until about halfway through and then binds. I tried to swap out the third unused spool with the spool that was binding but had similar results, so I think the problem lies in the valve body.
Does anyone have any experience servicing one of these valves? Is it worth my time to try and refurb this? I can't find any used valves on ebay and new units come in around $1200 - $1500. I've attached some pictures to try and give you a better idea of what I'm working with. Any and all suggestions appreciated. Let me know if any more info is required.
Spool valve - JD# AM124970 (dukes# 1415-AG / 156B7015)
Tractor - LV4400H
1 - 9 of 9 Posts
if it's the body, you may be able to have a machine shop clean it up a bit with a precision tool... whatever caused the damage - a burr, or piece of metal shaving etc - may only require some polishing to fix... with no material removal or machining per-se....
call a few hydraulics shops to see what they say... even if it takes them 2hrs to do (i would be surprised if it took that long), I can't see it costing more than $200.
As for the oil being "quite black"... well.... what can I say.... shame on you.
Good luck!
call a few hydraulics shops to see what they say... even if it takes them 2hrs to do (i would be surprised if it took that long), I can't see it costing more than $200.
As for the oil being "quite black"... well.... what can I say.... shame on you.
Good luck!
I think I will have to end up taking it into a shop. Too badif it's the body, you may be able to have a machine shop clean it up a bit with a precision tool... whatever caused the damage - a burr, or piece of metal shaving etc - may only require some polishing to fix... with no material removal or machining per-se....
call a few hydraulics shops to see what they say... even if it takes them 2hrs to do (i would be surprised if it took that long), I can't see it costing more than $200.
As for the oil being "quite black"... well.... what can I say.... shame on you.
Good luck!
. closest one is a 3hr drive.As for the fluid being black I can't really say why. Hydraulic fluid and filter were changed a little over a year ago (>200 hrs) and it definitely didn't look black when being drained. Is there a special procedure to flush the SCV? even when connecting/disconnecting hydraulic quick connects the fluid that dribbles out looks pretty good (clear and tan).
No U want this with the correct bore size. Not to tight and plenty of oil and slow back and forth. U can wrap crocus cloth on outside of hone to polish if need be. Hone has to have stones long enough to bridge the counterbore
This will do it if its really bunged up but I doubt it
A HSS Adjustable Blade Reamer
1 - 9 of 9 Posts
